不同氮源对典型赤潮藻类生长的影响

发布时间：2018-06-13 11:00

本文选题：海洋微藻 + 无机氮　；参考：《暨南大学》2016年硕士论文

【摘要】：本研究采集了广东沿海大亚湾、广海湾、桂山岛三个典型海域微表层和次表层水样,对不同形态的氮含量进行了测定,以揭示典型海域海水中氮营养盐结构及氮浓度水平。并且在实验室内模拟我国南海典型养殖区大亚湾海域的氮磷水平,选取代表不同类群的典型赤潮生物,包括硅藻中肋骨条藻(Skeletonema costatum)、甲藻海洋原甲藻(Prorocentrum micans)、针胞藻海洋卡盾藻(Chattonella marina),研究它们对不同无机和有机氮源(NO3-、尿素及多种氨基酸)、氮(N)浓度以及NO3-和尿素不同比例混合下的生长状况,并且测定了培养液中不同形态氮浓度的变化,以探讨不同类别的赤潮藻类对不同形态氮营养盐的利用能力。研究结果可为富营养化海域浮游植物群落结构的变化提供科学依据,对我国海洋环境的保护以及维护海洋生态系统的稳定具有一定意义。研究结果显示:1)本次调查中大亚湾、桂山岛和广海湾海域氮浓度均有显著上升,大亚湾和桂山岛海域的可溶性无机氮(DIN)含量已经达到我国二类海水水质标准,广海湾则已经超过我国三类海水水质标准;微表层对各种形态的N没有明显富集作用。2)氮营养盐结果也发生了明显变化,位于养殖区的大亚湾和桂山岛海域,可溶性有机氮(DON)含量远远超过DIN,可占可溶性总氮(DTN)含量的80%以上,有的甚至超过了90%。说明在养殖海域DON已经成为浮游植物可利用的主要N源;广海湾海域DON含量较低,但DIN较高,为浮游植物的生长提供了丰富的N源。3)中肋骨条藻能够利用NO3-、尿素、氨基酸等多种不同形态N源,在有机N源丰富的近岸海域具有竞争优势,这可能是该藻在全球近岸海域占据优势在重要原因;海洋原甲藻能利用NO3-和尿素,无法直接利用本研究中5种氨基酸形态的N源;海洋卡盾藻能够利用NO3-、尿素以及甘氨酸和丝氨酸,而且可以忍耐缺N环境,在DIN限制环境中具有一定竞争优势。4)中肋骨条藻、海洋原甲藻和海洋卡盾藻在不同比例NO3-和尿素复合N源下均生长良好,其中中肋骨条藻和海洋卡盾藻在复合N源条件下,藻细胞生长状况优于单一N源。5)中肋骨条藻、海洋原甲藻和海洋卡盾藻的半饱和常数分别为25.0μmol/L、2.29μmol/L和4.98μmol/L,说明中肋骨条藻对N的亲和力较低,在N含量丰富的条件下才能较好的生长,而近岸海域的富营养化为中肋骨条藻的生长提供了丰富的N源;海洋原甲藻和海洋卡盾藻对N的亲和力较高,在低N环境下具有较高的竞争力,因此在硅藻水华过后,营养盐含量下降时,这类有毒有害藻类容易占据浮游植物种群竞争优势,并引发赤潮。
[Abstract]:In this study, the microsurface and subsurface water samples of three typical sea areas, Daya Bay, Guangwan and Guishan Island, along the coast of Guangdong Province, were collected, and the nitrogen contents of different forms were determined to reveal the nitrogen nutrient structure and nitrogen concentration level in typical sea water. The nitrogen and phosphorus levels in Daya Bay, a typical culture area in the South China Sea, were simulated in the laboratory, and typical red tide organisms representing different groups were selected. Including Skeletonema costatumus, Prorocentrum micansa and Chattonella marinaanus in diatoms. The growth status of different inorganic and organic nitrogen sources, such as no _ 3, urea and various amino acids, nitrogen nitride (N _ N), and the mixture of no _ 3- and urea were studied. In order to study the utilization ability of different kinds of red tide algae to different forms of nitrogen nutrient, the change of nitrogen concentration in different forms of culture medium was determined in order to study the utilization ability of different species of red tide algae. The results can provide scientific basis for the change of phytoplankton community structure in eutrophication sea area and have certain significance for the protection of marine environment and the maintenance of marine ecosystem stability in China. The results showed that nitrogen concentrations in Daya Bay, Guishan Island and Guang Bay increased significantly in this survey, and the content of soluble inorganic nitrogen in the waters of Daya Bay and Guishan Island has reached the standard of Grade II seawater quality in China. The results of nitrogen nutrition in Guangwan Bay have also changed significantly, and they are located in the waters of Daya Bay and Guishan Island in the aquaculture area, which are located in the waters of Daya Bay and Guishan Island. The content of soluble organic nitrogen (DON) was much higher than that of din, which accounted for more than 80% of the total soluble nitrogen (DTNN) content, and some even exceeded 90%. The results show that don has become the main N source for phytoplankton in cultured sea area, and don content is low, but din is higher in Guang Gulf Sea area, which provides abundant N source for phytoplankton growth. 3) Costella costatum can utilize no _ 3-urea, and no _ 3-urea for phytoplankton growth. Many different forms of N sources, such as amino acids, have competitive advantages in the coastal waters with abundant organic N sources, which may be the important reason for the dominance of the algae in the global coastal waters, and marine Prorocentrum can utilize no _ 3- and urea. The N source of five amino acid forms in this study can not be directly utilized, and the marine chamomonas can utilize no _ 3, urea, glycine and serine, and can tolerate N deficiency, and has a certain competitive advantage in din restricted environment (.4). Marine Prorocentrum and Dioscorea grew well under different ratios of no _ 3- and urea compound N sources, and the growth status of the algal cells was better than that of the single N.) under the condition of compound N source, the growth status of the algal cells was better than that of the single N source. The semi-saturation constants of Prorocentrum and Dioscorea were 25.0 渭 mol / L, 2.29 渭 mol / L and 4.98 渭 mol / L, respectively, which indicated that the affinity of P. costatum to N was low and the growth was better under the condition of rich N content. The eutrophication in the coastal waters provides abundant N sources for the growth of S. costatum, and the affinity of Prorocentrum to N is high, and it is competitive in low N environment, so after the Shui Hua of diatom, When the nutrient content decreases, these poisonous and harmful algae tend to occupy the competitive advantage of phytoplankton population and cause red tide.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X55

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